Hi Mike, and welcome to the CE registry....
The stock ECM's should be pretty easy to find, lots of guys are changing them out of their 82's for a newer model that can be programmed on the fly... If no one here pops up with one try asking on the crossfire forum...
http://www.crossfire.homeip.net/
The metal tube is going to be the hard one, I pulled mine off, but another guy already has dibs on it if I ever decide to sell it... Your best bet is going to be to keep asking every where you go, and keep searching the online vette junk yards.
Heres a couple of links to get you started...
http://www.corvettejunk.com/
http://www.corvettepartssalvage.com/index.html
http://www.artscorvetteparts.com/
Try email them about the part and see if any of them have a lead...
For the rims, the only place I ever see any for sale is on Ebay, if we see any pop up for sale there, I'm sure we will let you know...